This invention relates to the field of gastrostomy tubes, which are used to deliver nutrients and/or medications directly to the stomach of an infirm patient. The gastrostomy apparatus of the present invention includes means for preventing leakage of gastric contents, and for reducing or eliminating irritation of the skin adjacent to the gastrostomy site.
It has been known to use gastric tubes to administer essential nutrient solutions and medications to persons with severe dysphagia. The gastric tube is inserted through a hole, or gastrostomy, in the abdominal wall and the stomach wall. The terms "gastric tubes" and "gastrostomy tubes" are used interchangeably in this specification.
Gastric tubes typically include a balloon at the distal end. The balloon, when inflated, anchors the gastric tube within the stomach. Examples of prior art gastrostomy tubes which have balloons at their distal ends are shown in U.S. Pat. Nos. 5,358,488 and 5,458,583. The typical prior art gastrostomy device also includes a retention disk, or its equivalent, which remains on the outside of the gastrostomy. Thus, when the gastrostomy apparatus is in use, the abdominal wall and the wall of the stomach are sandwiched between the inflated balloon and the disk. The disk provides some resistance to the peristaltic motions of the stomach, and prevents the gastric tube from migrating too far into the stomach.
A gastrostomy will inherently exert a constricting force on a gastric tube inserted therethrough, and this constriction tends to prevent gastric contents from leaking out onto the surrounding skin. However, in some patients, the constrictive pressure of the gastrostomy channel is ineffective in preventing leakage. The leaked material, which may include a mixture of feeding solutions, dissolved or suspended medications, and gastric secretions, irritates the skin around the gastrostomy. The result is inflammation, ulceration, and sometimes infection. Thus, the gastrostomy must be continually monitored for leakage.
To minimize the harm from potential leakage of gastric contents, it is necessary to take special care that gastric tubes and their immediate environments are kept clean. The gastric tube itself must be regularly flushed with water, and the skin surrounding the gastrostomy opening must be kept clean and dry.
When leakage is noted, caregivers may react by inflating the balloon, if it is not already fully inflated, and/or by adjusting the retention disk so that it allows the balloon to be conveniently positioned against the stomach wall. Leakage may also be countered by reducing the volume and/or flow rate of feeding. In order to stop persistent leakage, physicians have resorted to the use of gastrostomy tubes having progressively larger diameters, or to the administration of antacids and/or H2 blockers. Various local treatments, such as creams, pastes, and dressings, have also been applied around the gastrostomy. Usually such efforts are effective, but sometimes the gastric leakage continues and contacts the skin under the dressings.
In those patients in which the gastrostomy channel does not effectively prevent leakage, the use of larger diameter tubes does not solve the problem. Moreover, inflammatory secretions in the vicinity of the gastrostomy lubricate the gastric tube and allow the retention disk to slide, thus allowing the gastric tube to move in an undesired manner. In particular, the peristaltic motions of the stomach draw the gastric tube further into the stomach, and prevent the balloon of the gastric tube from being held continuously against the stomach wall to plug the opening in the stomach.
Thus, neither the balloon nor the retention disk solves the problem of gastric leakage. A caregiver may attempt to stop the leakage by increasing the pressure of the balloon against the stomach wall, and by fixing the retention disk with tape or some other means to make it hold its position. But this procedure has its own risks. Sandwiching of the tissues between the balloon and the retention disk may result in ischemia or necrosis of the gastric wall, or of the skin compressed by the balloon on one side and by the retention disk on the other.
When the possibility of a serious skin infection is high, it may be necessary to remove the gastric tube to prevent further damage to the patient's skin. Removal of the gastric tube allows the gastrostomy to close, and the patient must then be fed by a nasogastric tube until the abdominal skin wounds have healed.
The present invention solves the above-described problems, by providing a gastrostomy apparatus which minimizes leakage, and which also minimizes the harm encountered if some leakage does occur.